Of course, it will likely be a dystopia in which tens of thousands a people's lives will be saved, so there is that.

True, but it's a dangerous precedent. The fact is that a lot of law in areas such as traffic, waste management etc is basically meant to be fluid and a deterrent; if everybody that littered where it was illegal, drank from open containers where it was illegal, fly-tipped or sped was instantly caught, then we'd just have tonnes of people in prison for relatively minor offences.

I think there's a desirable degree of pragmatism to be favoured in lieu of unbounded technological utopianism on this point.

You don't (shouldn't) put people in prison for stuff like this, you keep fining them increasing amounts of money until they stop doing the thing they are not supposed to be doing. The world would be a much better place if the traffic (and waste) laws were more, maybe even automatically, enforced.

Case in point: http://www.nydailynews.com/news/world/singaporean-man-fined-...

I think a point system is better than fines. Fines are effective deterrents for most people, but they are unfair on the poor.

http://en.wikipedia.org/wiki/Point_system_%28driving%29

You could also have fines proportional to income. Both fines and point systems have their caveats though.

Philosophically speaking, no one will be saved. We are all basically dying. Of course it would be nice to reduce traffic deaths, but we should carefully consider in what way our actions will affect society.

We should not assume this will only affect how people behave in traffic, as well. Other offences will likely also be included.

How is that worse than a dash cam? Should those be banned so that you can have privacy when travelling on public roads?

They are illegal in Germany.